我正在编写一个允许您打开保存在计算机上的文件的程序，我按照Microsoft提供的文档示例。 （https://msdn.microsoft.com/en-us/library/system.windows.forms.openfiledialog.openfile(v=vs.110).aspx)The问题是，它实际上是不会读取数据，当你打开文件时，它就会回到你刚刚打开程序的时候。我想知道我错过了什么，让它读起来文件。
这是我的表格
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Lab12
{
public partial class Form1 : Form
{
//ref the class and create an array.
private EmployeesClass[] Employee = new EmployeesClass[SIZE];
//state any constants
const int SIZE = 10;
const int ZERO = 0;
const int ONE = 1;
private int counter = ZERO;
private int numEmployees = ZERO;
public Form1()
{
InitializeComponent();
}
//Exit Program
//Purpose: To Exit the program.
//Perameters: The sending objcet and event arguments.
//Returns: none
private void exitToolStripMenuItem1_Click(object sender, EventArgs e)
{
//closes the program
this.Close();
}
//Display about
//Purpose: To show detail about the program.
//Parameters: The sending objcet and event arguemts.
//Returns: Info about the program.
private void aboutToolStripMenuItem_Click(object sender, EventArgs e)
{
//This is display about info program
MessageBox.Show("Devin\nCS1400\nProjects #12");
}
//Emplyee info method
//Purpose: To return employee info saved on a file on the computer.
//Parameters: The sending objcet and event arguemts.
//Returns: Employee info
private void openToolStripMenuItem_Click(object sender, EventArgs e)
{
Stream myStream;
OpenFileDialog payRollFile = new OpenFileDialog();
payRollFile.InitialDirectory = "c:\\Documents";
payRollFile.Filter = "txt files (*.txt) | *.txt|All files (*.*)|*.*";
payRollFile.FilterIndex = 2;
payRollFile.RestoreDirectory = true;
if (payRollFile.ShowDialog() == DialogResult.OK)
{
try
{
if ((payRollFile.ShowDialog() != DialogResult.OK || (myStream = payRollFile.OpenFile()) != null))
return;
{
using (myStream)
{
StreamReader streamReader = new StreamReader(myStream);
string s = "test";
double employeeNumber = double.Parse(s);
string employeeName = streamReader.ReadLine();
string employeeAddress = streamReader.ReadLine();
s = streamReader.ReadLine();
string[] strArray = s.Split();
double hourlyWage = double.Parse(strArray[0]);
double hoursWorked = double.Parse(strArray[1]);
Employee[counter++] = new EmployeesClass(employeeNumber, employeeName, employeeAddress, hoursWorked, hourlyWage);
nextButton.Enabled = true;
numEmployees = this.counter;
counter = 0;
nameTxtBox.Text = Employee[counter].GetName();
addressTxtBox.Text = Employee[counter].GetAddress();
netPayTxtBox.Text = string.Format("{0:C}", Employee[counter].netPay());
}
}
}
catch (Exception ex)
{
MessageBox.Show("Error: Could not read file from disk. Original error:" + ex.Message);
}
}
}
// Next Button method
//Purpose: allows user to move forward through all of the data on the file.
//Parameters: Sender Objects , and event arguements.
//returns: The ablility to move forward through the data
private void nextButton_Click(object sender, EventArgs e)
{
//create a counter.
//counter++;
//create an if state ment that will let you click the button to move to the next item from the file
//as long as the counter is less then the number of the employees.
if (counter < numEmployees - ONE)
{
counter += ONE;
//get the names from the class, and display them in the name text box
nameTxtBox.Text = Employee[counter].GetName();
//get the Addresses from the class, and display them in the address text box
addressTxtBox.Text = Employee[counter].GetAddress();
//get the Total amount that the employee will take from the class, and display them in the pay text box
//convert the double to string
netPayTxtBox.Text = string.Format("{0:C}", Employee[counter].netPay());
}
else
{
//if there are no more items, have the button become disabled.
//then clear all of the boxes once it runs out of data.
nextButton.Enabled = true;
}
}
// Back Button method
//Purpose: allows user to move backwords through all of the data on the file.
//Parameters: Sender Objects , and event arguements.
//returns: The ablility to move backwards through the data
private void backButton_Click(object sender, EventArgs e)
{
//create a counter.
// counter--;
//create an if state ment that will let you click the button to move to the next item from the file
//as long as the counter is less then the number of the employees.
if (counter > ZERO)
{
counter -= ONE;
//get the names from the class, and display them in the name text box
nameTxtBox.Text = Employee[counter].GetName();
//get the Addresses from the class, and display them in the address text box
addressTxtBox.Text = Employee[counter].GetAddress();
//get the Total amount that the employee will take from the class, and display them in the pay text box
//convert the double to string
netPayTxtBox.Text = string.Format("{0:C}", Employee[counter].netPay());
}
else
{
//if there are no more items, have the button become disabled.
nextButton.Enabled = true;
}
}
//clear button method
//Purpose: Allows user to clear the text boxes manueley
//Returns Nothing.
private void clearButton_Click(object sender, EventArgs e)
{
nameTxtBox.Clear();
addressTxtBox.Clear();
netPayTxtBox.Clear();
}
}
}
这是我的班级
//EmplyeesClass
//Purpose: To determin how much an employee is payed, how much they have to pay in taxes, their address, and name, and employee number
//returns. Name, Address, How much they make after taxes.
class EmployeesClass
{
//stat any constants that will be used in this program
// such as full time hours, overtime payment, state tax percent, and Fedreal tax rate.
const int FULLTIME = 40;
const double OVERTIME = 0.5;
const double FEDTAXRATE = 0.075;
const double STATETAXRATE = 0.2;
const double ZERO = 0;
//set any variables that will be used in this class.
private double employeeNumber;
private string employeeName;
private string employeeAddress;
private double hourlyWage;
private double hoursWorked;
//create the Employees class that can be accessed in the open tool method.
public EmployeesClass(double employeeNumber, string employeeName, string employeeAddress, double hoursWorked, double hourlyWage)
{
this.employeeNumber = employeeNumber;
this.employeeName = employeeName;
this.employeeAddress = employeeAddress;
this.hoursWorked = hoursWorked;
this.hourlyWage = hourlyWage;
}
//create the method for payment of the employee
public double netPay()
{
//get the gross pay by mulitplying how many hours they work by what they make an hour.
double gross = hoursWorked * hourlyWage;
//if the employee worked more than 40 hours get them overtime
double overtime = hoursWorked - FULLTIME;
//take there gross and subrtract the state tax
double stateTax = gross * STATETAXRATE;
//take their gross and subtract the fedrual tax
double fedTax = gross * FEDTAXRATE;
//set up an if statement to determin if they get overtime pay
if (overtime > ZERO)
gross += overtime * (hourlyWage * OVERTIME);
//return the the amount of they have earned with overtime.
return gross - stateTax - fedTax;
}
//return the hours the employees have worked.
public double GetHours()
{
return hoursWorked;
}
//return the amount of money they have made the employees have worked.
public double NetWage()
{
return hourlyWage;
}
//return the the employees address.
public string GetAddress()
{
return employeeAddress;
}
//return the employees name.
public string GetName()
{
return employeeName;
}
}
}
以下是您可以保存到计算机上的txt文件的基本信息。
1
John MerryWeather
123 West Main Street
5.00 30
2
Andrew Buttons
17 East Riverview Drive
12.00 40
3
Martha Washington
1 Mount Vernon Lane
7.25 20
4
Harry Skilling
786 No. Rodeo Drive
8.00 45
5
Ann Mindbender
192 Wizard Street
9.00 40
6
Carl Zabriskie
42 No. State Street
10.50 42
答案 0 :(得分：0)
错误是由于以下行：
if ((payRollFile.ShowDialog() != DialogResult.OK || (myStream = payRollFile.OpenFile()) != null))
return;
第一次测试不应该在那里，你已经测试过了，对话框会出现两次。第二，如果(myStream = payRollFile.OpenFile())成功，它将为NOT null并返回，因此当事情正常时，您的方法就会返回。
应该是这样的：
if (myStream = payRollFile.OpenFile()) == null))
return;
其次，这一行将导致异常：
string s = "test";
double employeeNumber = double.Parse(s);
您将string分配给s，然后无法将其解析为double！